Related על בבא מציעא 176:19

The "granary" for tithes [of produce] (i.e., the point at which produce must be tithed) rendering one liable on account of the laws of tevel (i.e., the prohibited consumption of or benefit from untithed produce), is once their work is completed -- [meaning] the work of being brought in [from the field]. (See Bava Metzia 88b:6).)